Common Myths about Food Allergies

Food Allergy

There are a great deal of misconceptions when it comes to considering food allergy for pets. In this brief summary, we hope to bust a few myths and present an overview of the problem. A more detailed article on food allergies can be found in the Pet Health Care Library.

MYTH: “Food allergy ought to produce intestinal signs as it is the intestinal tract that is exposed to the allergen.”
FACT: In pets, it is usually the skin that suffers with a food allergy. Food allergy is one of the itchiest conditions in veterinary dermatology. Making matters worse is the fact that food allergies tend to be resistant to cortisone therapies which makes itch control especially difficult.

MYTH: “Food allergy is a less likely cause of my pet’s skin disease as we have been feeding the same food for years and the skin problem is a recent development.”
FACT: It takes time to develop a food allergy, typically months to years. The immune system must be exposed and must develop enough antibodies to trigger an allergic reaction and this requires multiple exposures to the food in question. A reaction to a food that occurs on the first exposure to that food is not an allergic reaction. Such reactions are called “food intolerances” and involve toxins within the food but not an allergic reaction.

MYTH: “Soy and corn are common food allergens and it is best to seek pet foods without these ingredients to avoid problems.”
FACT: The most common food allergens for dogs are: beef, dairy, and wheat. These three ingredients account for 68% of canine food allergies. The most common food allergens in cats are: beef, dairy, and fish. These three ingredients account for 80% of feline food allergies.

MYTH: “If it looks like my pet might have a food allergy, I should be able to manage the problem by switching to another diet.”
FACT: Unfortunately for food allergic pets, most pet food diets contain some sort of mixture of beef, dairy, wheat, lamb, fish, and chicken. This means that simply changing foods is bound to lead to exposure to the same allergens. There are two ways to address food allergy: feeding a diet based on a truly novel protein source (this usually means an exotic diet like venison, duck, kangaroo, rabbit or even alligator) OR feeding a diet where the protein has been pre-digested into units too small to interest the immune system.

MYTH: “My pet got only partly better after the food trial so that means it didn’t work.”
FACT: Animals commonly have several allergies concurrently. A food allergy responding to a test diet at the same time an inhalant allergy is active will look like a partial response. On the other side of the coin, an inhalant allergy can become inactive should the weather change substantially during the diet trial. This would make a diet appear to be successful by coincidence. In order to determine if a response to a diet trial is real, at the end of the trial the patient is challenged with the original diet. If itching re-starts within feeding 2 weeks of the challenge, food allergy can be diagnosed.


We don’t want to give away all the information here. Visit the complete site on food allergies in our library.